AP Bio Ch. 4 Vocab Quiz

ARROYO MR TRAN AP BIO

actin

A globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other kinds of cells.

cell wall

A protective layer external to the plasma membrane in the cell of plants, prokaryotes, fungi, and some protists. Polysaccharides such as cellulose (in plants and some protists), chitin (in fungi), and peptidoglycan (in bacteria) are important structural components of this.

central vacuole

In a mature plant cell, a large membranous sac with diverse roles in growth, storage, and sequestration of toxic substances.

centrioles

A structure in the centrosome of an animal cell composed of a cylinder of microtubule triplets arranged in a “9 plus 0” pattern. A centrosome has a pair of this thing.

centrosomes

A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. This has two centrioles.

chloroplasts

An organelle found in plants and photosynthetic protists that absorb sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water.

chromatin

The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, it exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope.

chromosomes

A cellular structure consisting of one DNA molecule and associated protein molecules. A eukaryotic cell typically has multiple, linear chromosomes, which are located in the nucleus. A prokaryotic cell often has a single, circular chromosomes, which is found in the nucleoid, a region that is not enclosed by a membrane.

cilia

(plural) A short appendage containing microtubules in eukaryotic cells. A motile cilium is specialized in eukaryotic cells. A motile cilium is specialized for locomotion or moving fluid past the cell; it is formed from a core of nine outer doublet microtubules and two inner single microtubules (the “9 plus 2” arrangement) ensheathed in an extension of the plasma membrane. A primary cilium is usually nonmotile and plays a sensory and signaling role; it lacks the two inner microtubules (the “9 plus 0” arrangement)

collagen

A glycoprotein in the extracellular matrix of animal cells that forms strong fibers, found extensively in connective tissue and bone; the most abundant protein in the animal kingdom.

contractile vacuoles

A membranous sac that helps move excess water out of certain freshwater protists

cristae

An infolding of the inner membrane of a mitochondrion. The inner membrane houses electron transport chains and molecules of the enzyme catalyzing the synthesis of ATP (ATP synthase)

cytoplasm

The contents of the cell enclosed by the plasma membrane; in eukaryotes, the portion exclusive of the nucleus

cytoskeleton

A network of microtubules, microfilaments, and intermediate filaments that extends throughout the cytoplasm and serves a variety of mechanical, transport, and signaling functions.

cytosol

The semifluid portion of the cytoplasm.

dyneins

In cilia and flagella, a large motor protein extends from one microtubule doublet to the adjacent toublet. ATP hydrolysis drives changes in dynein shape that lead to bending of cilia and flagella.

endomembrane system

The collection of membranes inside and surrounding a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles; includes the plasma membrane, the nuclear envelope, the smooth and rough endoplasmic reticulum, the Golgi apparatus, lysosomes, vesicles, and vacuoles.

endoplasmic reticulum (ER)

An extensive membranous network in eukaryotic cells, continuous with the outer nuclear membrane and compossed of ribosome-studded (rough) and robosome-free (smooth) regions.

endosymbiont theory

A theory that mitochondria and plastids, including chloroplasts, originated as prokyarotic cells engulfed by host cells. The engulfed cell and its host cell then evolved into a single organism. See also endosymbiosis.

eukaryotic cell

A type of cell with a membrane-enclosed nucleus and membrane enclosed organelles. Organisms with eukaryotic cells (protists, plants, fungi, and animals) are called eukaryotes.

fibronectin

An extracellular glycoprotein secreted by animal cells that helps them attach to the extracellular matrix.

flagella

(plural) A long cellular appendage specialized for locomotion. LIke motile cilia, eukaryotic flagella have a core with nine outer doublet microtubules and two inner single microtubules (the “9 plus 2” arrangement) ensheated in an extension of the plasma membrane. Prokaryotic flagella have a different structure.

glycoproteins

A protein with one or more covalently attached carbohydrates.

Golgi apparatus

An organelle in eukaryotic cells consisting of stacks of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum and synthesize some products, notably noncellulose carbohydrates.

integrins

In animal cells, a transmembrane receptor protein with two subunits that interconnects the extracellular matrix and the cytoskeleton.

intermediate filaments

A component of the cytoskeleton that includes filaments intermediate in size between microtubules and microfilaments.

lysosomes

A membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of animal cells and some protists.

microfilaments

A cable composed of actin proteins in the cytoplasm of almost every eukaryotic cell, making up part of the cytoskeleton and acting alone or with myosin to cause cell contraction; also known as an actin filament.

microtubules

A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella.

mitochondria

(plural) An organelle in eukaryotic cells that serves as the site of cellular respiration; uses oxygen to break down organic molecules and synthesize ATP

myosin

A type of motor protein that associates into filaments that interact with actin filaments, causing cell contraction.

nuclear envelope

In a eukaryotic cell, the double membrane that surrounds the nucleus, perforated with pores that regulate traffic with the cytoplasm. The outer membrane is continuous with the endoplasmic reticulum.

nucleoid

A non-membrane-enclosed region in a prokaryotic cell where its chromosome is located.

nucleolus

A specialized structure in the nucleus consisting of chromosomal regions containing ribosomal RNA (rRNA) genes along with the ribosomal proteins imported from the cytoplasm; site of rRNA synthesis and ribosomal subunit assembly.

nucleus

An atom's central core, containing protons and neutrons. (2) The organelle of a eukaryotic cell that contains the genetic material in the form of chromosomes, made up of chromatin. (3) A cluster of neurons.

organelles

Any of several kinds of membrane enclosed structures with specialized functions, suspended in the cytosol of eukaryotic cells.

peroxisome

An organelle containing enzymes that transfer hydrogen atoms from various substrates to oxygen (O2), producing and then degrading hydrogen peroxide (H2O2).

phagocytosis

A type of endocytosis in which large particulate substances or small organisms are taken up by a cell. It is carried out by some protists and by certain immune cells of animals (in mammals, mainly macrophages, neutrophils,k and dendritic cells)

plasma membrane

The membrane at the boundary of every cell that acts as a selective barrier, regulating the cell’s chemical composition.

plasmodesmata

An open channel through the cell wall that connects the cytoplasm of adjacent plant cells, allowing water, small solutes, and some larger molecules to pass between the cells.

plastids

One of a family of closely related organelles that includes chloroplasts, chromoplasts, and amyloplasts. Plastids are found in the cells of photosynthetic eukaryotes.

prokaryotic cell

A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with prokaryotic cells (bacteria and archaea) are called prokaryotes

proteoglycans

A large molecule consisting of a small core protein with many carbohydrate chains attached, found in the extracellular matrix of animal cells. May consist of up to 95% carbohydrate.

rough ER

That portion of the endoplasmic reticulum with ribosomes attached.

smooth ER

That portion of the endoplasmic reticulum that is free of ribosomes.

thylakoids

A flattened, membranous sac inside a chloroplast. Thylakoids often exist in stacks called grana that are interconnected; their membranes contain molecular “machinery” used to convert light energy to chemical energy.

vacuoles

A membrane-bounded vesicle whose specialized function varies in different kinds of cells.

vesicles

A membranous sac in the cytoplasm of a eukaryotic cell.